Term
| What NK (natural killer) cells do |
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Definition
Use perforin and granzymes to induce apoptosis in virally infected cells and tumor cells (Tc (CD8+) T cells also do this)
Kill cells with nonspecific activation signals or one's missing class I MHC on surface |
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Term
| Hyperacute organ rejection is mediated by ___ cells |
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Definition
| B cells (type III hypersensitivity) |
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Term
| Acute organ rejection is mediated by ___ cells |
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Definition
T cells
(type IV delayed hypersensitivity) |
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Term
| Chronic organ rejection is mediated by ___ cells |
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Definition
T cells
(type IV delayed hypersensitivity) |
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Term
| 2 signals required to activate naive T cells (either Th or Tc) |
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Definition
1. Antigen presentation on MHC (MHCII for Th, MHCI for Tc) of dendritic cell to T-cell receptor (in combination with CD4 or CD8)
2. Costimulatory signal by B7 on DC with CD28 on naive T cell |
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Term
| 3 steps required for B cell activation and class switching |
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Definition
1. Antigen presentation on MHC II of B cell to Th cell receptor
2. CD40 on B cell binds CD40 ligand (CD40L) on Th cell
3. Th cell secretes cytokines determining the class that B cell will switch to |
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Term
| 2 cytokines secreted by Th1 cells and what cytokine inhibits Th1 cells |
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Definition
Secrete IL-2 and IFN-γ
Inhibited by IL-10 (from Th2 cell) |
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Term
| 4 cytokines secreted by Th2 cells and what cytokine inhibits Th2 cells |
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Definition
Secrete IL-4, IL-5, IL-6, and IL-10
Inhibited by IFN-γ (from Th1 cell) |
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Term
| What cytokine(s) activate macrophages? |
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Definition
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Term
What cytokines do macrophages release?
What's the result? |
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Definition
IL-1 and TNF-α
(stimulates lymphocytes, causing them to make more IFN-γ, further activating the macrophages) |
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Term
| What part of an antibody is the Fab region? |
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Definition
| The two arms, for antigen binding |
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Term
| What part of an antibody is the Fc region? |
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Definition
Is single branch
Is the constant region (carboxy terminal) where complement can bind
Determines the isotype of the antibody (ex. IgG, IgE, etc) |
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Term
| MAC complex is effective against what microbes? |
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Definition
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Term
| Function of Cb complement component |
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Definition
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Term
| What mediates the classic complement pathway? |
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Definition
| IgM or IgG (other complement pathways just use innate immune system) |
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Term
| What kind of antigens are expressed on MHC I molecules and how? |
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Definition
Antigen from intracellular peptides (think viruses) is loaded in RER, and pairs with β2-microglobulin (aids in transport to cell surface).
(MHC I is on nearly all nucleated cells and presents to CD8+ T cells) |
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Term
| What kind of antigens are expressed on MHC II molecules and how? |
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Definition
Antigen of extracellular origin is endocytosed, and then has its invariant chain released in an acidified endosome.
(On APCs, presents to CD4+ T cells) |
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